About four kinds of briquett which differ one another in the quantity of volatile matter, the heat of carbonization was calculated from the combination of experimental data and equation derived by the authors.As the result, it was ascertained that the relation of direct proportion is nearly formed between the quantity of volatile matter and heat of carbonization.
On the other hand, about kaolin, the heat of thermal decomposition was calculated using the same way for the purpose of examining above-mentioned values, and it became clear that the heat of thermal decomposition of kaolin can be calculated within the limit of error of a few percents deviating from the well known value.
Consequently, it is believed by the authors that the values of heat of carbonization calculated are appropriate.